1. Field of the Invention
This invention relates to a Karl-Fischer reagent the solvent of which is an alkylene carbonate.
2. Description of the Prior Art
Karl-Fischer reagent has been known and is a solution of iodine, sulfur dioxide and pyridine in an appropriate solvent. Various solvents of the Karl-Fischer reagent have been known. In view of stability of the reagent, chloroform is preferred (refer to Japanese Patent Publication No. 1748/58). A combination of chloroform with a small amount of a glycol gives more stable reagent (refer to Japanese Patent Publication No. 2598/63).
The inventors have conducted intensive studies to find a Karl-Fischer reagent having good stability using a solvent other than chloroform and have found that, with the use of an alkylene carbonate, a Karl-Fischer reagent of good stability can be prepared. Thus, this invention was developed on the basis of this knowledge.